Damper controller



Feb. 9, 1943. J. E. HAINES ET AL 2,310,364

DAMPER CONTROLLER Filed Oct. 11, 1939 l. 9: 1o 1 n I no '1? '00 m John E. Haines 95 Fig.6a. Gordon 15. Ildj-ng 6 stanlegwMicke-lls Patented Feb. 9, 1943 2,310,364 DAMPER CONTROLLER John E.

liaines, Gordon F.

Laing, and Stanley W.

Nickells, Chicago, lll., asslgnors to Minneapolis- Honeywell Regulator Comp any,

Minneapolis,

Minn, a corporation of Delaware Application October 11, 1939, Serial No. 298,924

8 Claims.

4 invention relates to damper load compensators which can \be readily installed on furnaces. More specifically, our invention pertains to means to compensate for the weight of the dampers, to thereby obtain more sensitive operation thereof.

The draft and check dampers usually provided on a furnace are ordinarily formed of heavy cast metal. It is also a common practice to have the damper regulator operate the dampers by sequentially lifting said dampers off their respective seats. Because of the weight of the dampera, the damper motor will have a substantial reversal loss after one of the dampers is set down on its seat and before the second damper is lifted oil its seat. In many installations this reversal loss amounts to 30 to 40 degrees F. of boiler water temperature, or 1% to 2 pounds of steam pressure. Therefore, when a damper controller actuates heavy dampers there is no accurate control of the steam pressure or boiler water temperature.

Most furnace dampers are mounted upon a door, or upon a damper seat casting. They are often of different sizes and shapes suitable to the particular installation. Also, different manufacturers build different sizes, shapes, and weights of dampers, doors, and the accompanying fittings, These variations make it very difficult, or impossible, to actually counterbalance, or counterweight, each damper as it is installed upon the furnace.

It is an object of this invention to compensate the damper controller for the weight of the damper.

Another object is to provide damper weight compensating means which are adaptable to existing furnace installations.

A further object is to provide a compact device to accomplish the results of the preceding objects which will be very simple to install and adjust.

Other objects will be apparent in the specification, claims, and by reference to the accompanying drawing in which:

Figure 1 is .a diagrammatic view of a form of our invention as applied to a hot water furnace,

Figure 2 is a diagrammatic view of another form showing different modifications,

Figures 3 and 4 are detail views of one form shown in Figure 2,

Figures 5 and 6 are modifications,

Figure 6a is a detail view of a part shown in Figure 6, and

The present diagrammatic views of Figure I is a diagrammatic view of another embodiment of the invention.

In Figure 1 a furnace I0 is conventionally provided with a draft port ll, draft damper i2, flue i3, and a check damper H, which cooperate with a. boiler temperature responsive damper motor ii to control the flow of air through the furnace ill.

The damper motor I5 is provided with a base l1 which is screwed into the furnace ill at It. A volatile filled temperature bulb l9 extends into the furnace Ill and communicates with the diaphragms 23 within the motor l5. Therefore a rise in temperature at the bulb I! will cause an increased pressure within the bulb and within the diaphragms 20 thus causing them to expand. The movement of the diaphragms 20 is transferred to a stem 2i which protrudes through a hole in the top of an upper part of the casing l6 and, by such movement, rocks a channel member 22 about a pivot 23 which is suitably secured by a bracket 2| to the upper part of the casing IS. The channel member 22 is provided with an arm 25 which extends to the left of the pivot point 23 and. carries a weight 26 which may be moved to different positions along the arm 25 to vary the force acting downwardly upon the stem 2i. Thus a. manual adjustment is obtained to cause the motor IE to actuate the dampers i2 and M at selectively different temperatures.

The channel member 22 is provided with a second pivot 28 upon which an arm 30 is rotatably mounted. The arm 30 is connected to the check damper H by a chain 3|. A second arm 32 is rotatably mounted on the pivot 23 and is connected to the draft damper l2 by the chain 33. The arm 32 has an abutting end 34 which is adapted to engage the channel member 22 to thereby cause the draft damper l2 to open when the channel member 22 is being rotated counterclockwise by the weight 26 due to a lowering of the boiler temperature. The arm 30 is provided with an abutting portion 35 which is adapted to engage the channel member 22 to cause the check damper It to open when the channel member 22 is being rotated clockwise by the motor l5 due to a rise of the boiler temperature. The arm 32 is provided with a screw stem 35 and the arm 30 is provided with a screw stem 31 which are connected by a spring 38. These screw stems form adjustable bell cranks in cooperation with the arms 30 and 32 as they are pivoted around their pivot points 28 and 23, respectively. The length of the arms thus formed by the screw stems 36 and 31 may be varied by changing the depth to which they are screwed into their respective lever arms 82 and 3B and will change the eil'ect oi the spring 38 upon the lever arms 30 and 12. Therefore, an adjustment can be made for dampers which are of different weights or operate through diil'erent angles.

In operation the spring 38 is adapted to compensate the regulator for the weight of the dampers i2 and i4. In the position shown in Figure 1 the check damper i4 is closed and the draft damper II is open. Assuming now. for example, that the weight of the dampers i2 and I4 acting on the motor i5 is two pounds each and the force exerted on the arms Ill and 32 by the spring 38 through the bell crank arrangements is 1% pounds: then, even though the check damper i 4 is in closed position there is still a 1% pound force tending to open said damper. Likewise when the draft damper I2 is in closed position and the check damper i4 is in open position the spring 88 will be exerting a similar 1% pound force tending to open the damper II. It is seen that even when the dampers are in closed position, they are actually only engaging their damper seats by a force amounting to approximately /4 of a pound. Therefore when the pressure motor i5 is moving to close one of the dampers and to subsequently open the second damper the additional weight that the damper motor needs to pick up is only of a pound rather than the entire weight of the damper. Thus the reversal loss which results when the motor is merely building up enough force to overcome the dead weight of the damper before that damper can be moved away from its seat is substantially reduced. So it is seen that by connecting the arms 30 and 32 by means of the screw stems 36 and 31 and the spring 38 that the weight of the dampers is in effect counterbalanced except for ,4 of a pound. This actual seating weight can be lower or higher 11 desired. It is also seen that by resiliently connecting the two dampers, the weight of one of the dampers, even though it is upon its seat, is still eflectively counterbalancing the weight of the other damper to a certain extent because of the unique arrangement of the spring 38 and the abutting stops 34 and 35.

Referring now to Figure 2 the damper motor is is adapted to cooperate with an arm 39 which has a weight 40 adapted to oppose the movement of the stem ii of the motor ii. The left hand end of the arm 39 is rovided with a bracket 4i to which an arm 42 is rotatably mounted by a pivot 43. The arm 42 is provided with a weight 44 which may be adjustably positioned upon the arm 42. The weight 44 also serves as a stop in opening the damper (not shown) by abutting the arm 39. On the opposite end of the arm 42 a damper chain 45 can be connected.

By using a weight type of counterbalancing means, substantially the same result is obtained as in using the spring type of counterbalancing means hereinbefore described. Assuming, for example, that the damper connected to the chain 45 exerts a downward force of 2 pounds and the weight 44 weighs 1% pounds and both are effectively equidistant from the pivot 43; then, when the damper connected to the chain 45 is in closed position, the arm 39 is still supporting the weight of the weight 44 as well as the amount of weight of the damper connected to the chain 45 that is counterbalanced by said weight 44. In other words, the arm 39 supports 3% pounds (weight of damper plus weight 44) ,when the damper is open and 3 pounds (counterbalanced weight of damper plus weight 44) when the damper is closed. Thus it is seen that when the damper connected to chain 45 is in closed position the weight 44 will act to, in ei'i'ect, counterbalance for almost all of theweight of the damper.

Referring now to Figures 3 and 4; a detailed view is shown of that form of our invention mounted on the right hand end of the lever arm 38 and is generally indicated by the reference character 50. A short lever arm 5! extends through a slot (not shown) in a protective casing 52 and is connected to a chain 63 which in turn connects to a damper (not shown). The arm ii is an extended portion of a circular plate 54 which is free to ivot about a stationary hub 55 suitably connected to the arm 39. The hub 55 is resiliently connected to notches 5B in the plate 54 by a spiral spring 51. The spring 51 is preferably one of open convolutions so that the parts of the spring will not rub against each other and cause spring friction in the operation of the device. The plate 54 is provided with an inturned car 58 which is adapted to abut the arm 40 when that arm has been raised to a predetermined position to cause opening of the damper connected to the chain 53. The spring 51 is adapted to substantially counterbalance the weight of the damper connected to the chain 53. For example, the spring might exert a force of 1 pounds to the lever 5i when used with a damper that exerted a downward force of 2 pounds. Diilerent springs may be easily inserted into the device for different weight dampers. and a diiferent initial tension on the spring may be obtained by moving the free end of the spring into different notches 56 in the plate 54. Therefore this type of device, like the others hereinbefore described. is adapted to effectively counterbalance for the weight of the damper when the damper to which it is connected by the spring 53 is in engagement with its seat.

Referring now to Figure 5 the pressure motor l5 has a stern 2| adapted to actuate an arm 60. A weight BI is mounted on the arm to oppose the operation of the pressure motor IS. A damper weight compensating mechanism, generally indicated by the reference character 82, is mounted on a bracket on the left hand end of the arm 60. A bell crank 64 is pivotally mounted upon the bracket 63 by a pin 65. One arm of the bell crank 64 is connected to a damper chain 68. The other arm of the bell crank 64 is connected to a spring 61 which is in turn connected to a bracket 68 secured to the arm 60 in a conventional manner. A pair of stops 69 are provided on the bracket 63 and serve to limit the movement of the bell crank 64. The operation of this form of our invention is similar to the operation of those hereinbefore described. The effect of spring 51 is to continue to exert force upon the arm 60 even when the damper connected to the chain 66 is seated.

Mounted on the right hand end of the arm 50 is another form of compensating mechanism which embodies the use of a compression spring H. This spring 1| is secured to the arm 60 by a U-shaped support 12 which is adapted to hold the spring H by its out-turned ends 13. The topmost convolution of the spring ll 15 inturned and extended downwardly through the interior of the spring, and the end is looped to form a connection 14 to which a damper chain 15 can be attached. The function of this form of weight compensator is substantially forms hereinbeiore described in that it acts to exert a force upon the damper motor arm even when the damper is in the closed position.

Referring now to Figure 6: the damper motor I! has the operating stem Ii in cooperative relation with an arm 0. The arm II is provided with a weight It which is adapted to oppose the movement of the motor ill. The extremities of the arm I. are provided with compensating means generally indicated by the reference characters I and It. The parts used in each of the compensators are identical and are merely arranged flre fly so as to show their application on damper motors where the clearance above or be low the extremities of the damper arms are dinerent, therefore only one of them will be explained in detail. The compensator 83 comprises a leaf spring I suitably secured to the arm 80 by a clip CI. The leaf spring 84 is provided with a downturned end It which is adapted to be inserted into holes on the top of the arm 8|! as is indicated at ll. The opposite end oi the leaf spring ill is arcuately formed as indicated at 88. A link II is adapted to fit looselyover the arm 80 which extends through a slot ii in the link 90. Holes 02 are provided whereby the damper chain 83 may be hooked to the link 90 at different heights. The link may be used with the slot Si in an upward position as is shown in the compensatorarrangement generally indicated at 83 or it can be used with the slot 81 in a downward position as used in the compensator-arrangement indicated at 82. The eflect of this compensator in operation is substantially the same as that in the other forms hereinbeiore described in that it tends to exert a force upon the damper arm 80 even when the damper is in the closed position.

Referring now to Figure '1; the damper motor ll cooperates with a damper arm iflil which is provided with a weight iili that is adapted to oppose the movement of the stem ll of the motor. A damper chain I02 connects the damper arm ill with a damper load compensator generally indicated by the reference character "it. The compensator III! is adapted to be mounted upon the damper and is shown as mounted to a lug HM upon a damper ill! by a screw M6. The compensator ill! comprises a coil spring iill secured to a fixed support I" at one end. A free end I" of the spring I! is turned to form a loop to which the damper chain I02 is secured. A stop H0 is provided to limit the movement of the free end ill of the spring I. The operation of this form of our invention is substantially the same as the function of those forms 'hereinbefore described in that the spring Hi1 tends to exert a force upon the damper motor arm lilil even when the damper I0! is seated.

While we have shown some modifications oi our invention in applications where different forms have been used on diflerent extremities of the damper motor am. it will be understood that the same type of compensator could be used on either end, or that different types might be used on either end as shown. It will also be obvious that for different sizes and weights of dampers diiferent modifications might prove to be the best applicable. Therefore it should be clearly understood that we are not to be limited in our invention only to those forms and combinations shown and described but by the spirit and scope or the appended claims.

the same as the We claim as our invention:

1. A damper mechanism comprising, in combination, a damper movable into and out of engagement with a damper port, a damper motor for moving said damper, said damper exerting a force upon said motor when away from said port, a damper arm operated by said motor, a coiled spring carried by said arm. a lever also carried by said arm adiustably secured to said spring, said spring exerting a force at all times tending to move said damper out of engagement with said port to compensate said motor for the weight of said damper, and connecting means between said damper, said motor, and said spring.

2. A damper mechanism comprising, in combination, a damper movable into and out of en gagement with a damper port, a damper motor for moving said damper, said damper exerting a force upon said motor when away from said port, a damper arm operated by said motor, a coiled spring carried by said arm, a lever also carried by said arm adjustably secured to said spring, said spring exerting a force at all times tending to move said damper out of engagement with said port, connecting means between said damper, said motor, and said spring, and a stop carried by said lever engogeable with said arm upon movement thereof in a damper opening direction to form a non-yieldable connection between said motor and said damper for moving said damper away from said port.

3. A damper mechanism comprising, in combination, a damper movable into and out of engagement with a damper port, a damper motor for moving said damper, said damper exerting a force upon said motor when away from said port; a damper arm operated by said motor, connecting means between said motor and said damper, a biasing means located in said connection between said motor and said damper, said biasing means exerting a force at all times tending to move said damper out of engagement with said port, and a stop means forming a nonyieldable connection between said motor and said damper for moving said damper away from said port.

4. A damper mechanism comprising, in combination, a damper movable into and out of engagement with a damper port, a damper motor for moving said damper, said damper exerting a force upon said motor when away from said port, a damper arm operated by said motor, a biasing means supported entirely by said arm, said biasing means exerting a force at all times tending to move said damper out of engagement with said port, connecting means between said damper, said motor, and said biasing means, and a stop means forming a non-yieldable connection between said motor and said damper for moving said damper away from said port.

5. In a heating system, in combination, fuel burning means including a draft damper and a check damper, a chamber associated with said iuel burning means and adapted to expand on increased rates of heat production within said fuel burning means, pivoted lever means adapted to be positioned by expansion and contraction of said chamber, connections between said lever means and said dampers for opening said draft damper when heat is being produced at a relatively low rate and for opening said check damper when heat is being produced at a relatively high rate. biasing means interposed in one of said connections acting in a direction tending to cause opening of the damper to which said connection is attached, and stop means for rendering said biasing means ineffective at values of force above a predetermined magnitude transmitted by said lever to said connection, whereby the force transmitted to said lever means by said chamber necossary to open said damper means is only slightly greater than the force necessary to load said resilient means to the point Where said stop means is effective.

6. In a heating system, in combination, fuel burning means including a draft damper and a check damper, a chamber associated with said fuel burning means and adapted to expand on increased rates of heat production within said fuel burning means, pivoted lever means adapted to be positioned by expansion and contraction of said chamber, connections between said lever means and said dampers for opening said draft damper when heat is being produced at a relatively low rate and for opening said check damper when heat is being produced at a relatively high rate, resilient biasing means interposed in one of said connections acting in a direction tending to cause opening of the damper to which said connection is attached, and stop means for rendering said resilient biasing means ineffective at values of force above a predetermined magnitude transmitted by said lever to said connection, whereby the force transmitted to said lever means by said chamber necessary to open said damper means is only slightly greater than the force necessary to load said resilient means to the point where said stop means is effective.

'7. A damper mechanism comprising, in combination, first and second dampers movable into and out of engagement with corresponding ports, a fluid pressure actuated damper motor for moving said dampers out of engagement with their ports selectively, the first or said dampers exerting a force upon said motor when away from its port, an arm operated by said motor, first connecting means between said arm and said first damper, said first connecting means having a variable effective length, biasing means associated with said first connecting means and tending to vary the effective length thereof in a direction tending to open said first damper, stop means for limiting the effective length of said first connecting means so that said motor may positively open said first damper, and second connecting means between said arm and said second damper, said second connecting means being separate from said first connecting means.

8. A damper mechanism comprising, in combination, first and second dampers movable into and out of engagement with corresponding ports, a fluid pressure actuated damper motor for moving said dampers out of engagement with their ports selectively, the first of said dampers exerting a force upon said motor when away from its port, an arm operated by said motor, first connecting means between said arm and said first damper, said first connecting means having a variable effective length, a spring means associated with said first connecting means and tending to vary the efiective length thereof in a direction tending to open said first damper, stop means for limiting the effective length of said first connecting means so that said motor may positively open said first damper, and second connecting means between said arm and said second damper, said second connecting means being separate from said first connecting means.

JOHN E. HAINES. GORDON F. LAING. STANLEY W. NICKELLS. 

